help - convert digicam's .mov format to .avi or other

i have konica minolta dimage z2 digicam... when transferred to computer, the moving clips are in .mov format with a 15 sec clip around 5MB

without changing the duration of clip, how cud i decrease the size of the file around 500k to 1mb? its ok if sound is deleted...

which shud be the best format? avi? dat? or some other? it should be able to play in WMP so that everybody can see it whom i fwd.

which converter to be used?

thanks

a_medico